3 files changed, 20 insertions, 9 deletions
diff --git a/app/helpers/diff_helper.rb b/app/helpers/diff_helper.rb
index 162778ade58..1b10795bb7b 100644
--- a/app/helpers/diff_helper.rb
+++ b/app/helpers/diff_helper.rb
@@ -7,14 +7,23 @@ module DiffHelper
     end
   end
 
-  def safe_diff_files(diffs)
-    diffs.first(allowed_diff_size).map do |diff|
-      Gitlab::Diff::File.new(diff)
+  def allowed_diff_lines
+    if diff_hard_limit_enabled?
+      Commit::DIFF_HARD_LIMIT_LINES
+    else
+      Commit::DIFF_SAFE_LINES
     end
   end
 
-  def show_diff_size_warning?(diffs)
-    diffs.size > allowed_diff_size
+  def safe_diff_files(diffs)
+    lines = 0
+    safe_files = []
+    diffs.first(allowed_diff_size).each do |diff|
+      lines += diff.diff.lines.count
+      break if lines > allowed_diff_lines
+      safe_files << Gitlab::Diff::File.new(diff)
+    end
+    safe_files
   end
 
   def diff_hard_limit_enabled?
diff --git a/app/views/projects/diffs/_diffs.html.haml b/app/views/projects/diffs/_diffs.html.haml
index b49aee504fe..ec8974c5475 100644
--- a/app/views/projects/diffs/_diffs.html.haml
+++ b/app/views/projects/diffs/_diffs.html.haml
@@ -5,11 +5,13 @@
       = parallel_diff_btn
   = render 'projects/diffs/stats', diffs: diffs
 
-- if show_diff_size_warning?(diffs)
-  = render 'projects/diffs/warning', diffs: diffs
+- diff_files = safe_diff_files(diffs)
+
+- if diff_files.count < diffs.size
+  = render 'projects/diffs/warning', diffs: diffs, shown_files_count: diff_files.count
 
 .files
-  - safe_diff_files(diffs).each_with_index do |diff_file, index|
+  - diff_files.each_with_index do |diff_file, index|
     = render 'projects/diffs/file', diff_file: diff_file, i: index, project: project
 
 - if @diff_timeout
diff --git a/app/views/projects/diffs/_warning.html.haml b/app/views/projects/diffs/_warning.html.haml
index 47abbba2eb2..bd0b7376ba7 100644
--- a/app/views/projects/diffs/_warning.html.haml
+++ b/app/views/projects/diffs/_warning.html.haml
@@ -14,6 +14,6 @@
           = link_to "Email patch", merge_request_path(@merge_request, format: :patch), class: "btn btn-warning btn-sm"
   %p
     To preserve performance only
-    %strong #{allowed_diff_size} of #{diffs.size}
+    %strong #{shown_files_count} of #{diffs.size}
     files are displayed.